/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <errno.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

#include "alloc-util.h"
#include "escape.h"
// #include "extract-word.h"
#include "fileio.h"
#include "gunicode.h"
#include "locale-util.h"
#include "macro.h"
#include "memory-util.h"
#include "string-util.h"
#include "strv.h"
// #include "terminal-util.h"
#include "utf8.h"
#include "util.h"

// char* first_word(const char *s, const char *word) {
//         size_t sl, wl;
//         const char *p;
// 
//         assert(s);
//         assert(word);
// 
//         /* Checks if the string starts with the specified word, either
//          * followed by NUL or by whitespace. Returns a pointer to the
//          * NUL or the first character after the whitespace. */
// 
//         sl = strlen(s);
//         wl = strlen(word);
// 
//         if (sl < wl)
//                 return NULL;
// 
//         if (wl == 0)
//                 return (char*) s;
// 
//         if (memcmp(s, word, wl) != 0)
//                 return NULL;
// 
//         p = s + wl;
//         if (*p == 0)
//                 return (char*) p;
// 
//         if (!strchr(WHITESPACE, *p))
//                 return NULL;
// 
//         p += strspn(p, WHITESPACE);
//         return (char*) p;
// }

// char *strnappend(const char *s, const char *suffix, size_t b) {
//         size_t a;
//         char *r;
// 
//         if (!s && !suffix)
//                 return strdup("");
// 
//         if (!s)
//                 return strndup(suffix, b);
// 
//         if (!suffix)
//                 return strdup(s);
// 
//         assert(s);
//         assert(suffix);
// 
//         a = strlen(s);
//         if (b > SIZE_MAX - a)
//                 return NULL;
// 
//         r = new(char, a+b+1);
//         if (!r)
//                 return NULL;
// 
//         memcpy(r, s, a);
//         memcpy(r+a, suffix, b);
//         r[a+b] = 0;
// 
//         return r;
// }

// char *strjoin_real(const char *x, ...) {
//         va_list ap;
//         size_t l = 1;
//         char *r, *p;
// 
//         va_start(ap, x);
//         for (const char *t = x; t; t = va_arg(ap, const char *)) {
//                 size_t n;
// 
//                 n = strlen(t);
//                 if (n > SIZE_MAX - l) {
//                         va_end(ap);
//                         return NULL;
//                 }
//                 l += n;
//         }
//         va_end(ap);
// 
//         p = r = new(char, l);
//         if (!r)
//                 return NULL;
// 
//         va_start(ap, x);
//         for (const char *t = x; t; t = va_arg(ap, const char *))
//                 p = stpcpy(p, t);
//         va_end(ap);
// 
//         *p = 0;
// 
//         return r;
// }

char *strstrip(char *s) {
        if (!s)
                return NULL;

        /* Drops trailing whitespace. Modifies the string in place. Returns pointer to first non-space character */

        return delete_trailing_chars(skip_leading_chars(s, WHITESPACE), WHITESPACE);
}

char *delete_chars(char *s, const char *bad) {
        char *f, *t;

        /* Drops all specified bad characters, regardless where in the string */

        if (!s)
                return NULL;

        if (!bad)
                bad = WHITESPACE;

        for (f = s, t = s; *f; f++) {
                if (strchr(bad, *f))
                        continue;

                *(t++) = *f;
        }

        *t = 0;

        return s;
}

char *delete_trailing_chars(char *s, const char *bad) {
        char *c = s;

        /* Drops all specified bad characters, at the end of the string */

        if (!s)
                return NULL;

        if (!bad)
                bad = WHITESPACE;

        for (char *p = s; *p; p++)
                if (!strchr(bad, *p))
                        c = p + 1;

        *c = 0;

        return s;
}

char *truncate_nl(char *s) {
        assert(s);

        s[strcspn(s, NEWLINE)] = 0;
        return s;
}

char ascii_tolower(char x) {

        if (x >= 'A' && x <= 'Z')
                return x - 'A' + 'a';

        return x;
}

char ascii_toupper(char x) {

        if (x >= 'a' && x <= 'z')
                return x - 'a' + 'A';

        return x;
}

char *ascii_strlower(char *t) {
        assert(t);

        for (char *p = t; *p; p++)
                *p = ascii_tolower(*p);

        return t;
}

char *ascii_strupper(char *t) {
        assert(t);

        for (char *p = t; *p; p++)
                *p = ascii_toupper(*p);

        return t;
}

char *ascii_strlower_n(char *t, size_t n) {
        if (n <= 0)
                return t;

        for (size_t i = 0; i < n; i++)
                t[i] = ascii_tolower(t[i]);

        return t;
}

int ascii_strcasecmp_n(const char *a, const char *b, size_t n) {

        for (; n > 0; a++, b++, n--) {
                int x, y;

                x = (int) (uint8_t) ascii_tolower(*a);
                y = (int) (uint8_t) ascii_tolower(*b);

                if (x != y)
                        return x - y;
        }

        return 0;
}

int ascii_strcasecmp_nn(const char *a, size_t n, const char *b, size_t m) {
        int r;

        r = ascii_strcasecmp_n(a, b, MIN(n, m));
        if (r != 0)
                return r;

        return CMP(n, m);
}

bool chars_intersect(const char *a, const char *b) {
        /* Returns true if any of the chars in a are in b. */
        for (const char *p = a; *p; p++)
                if (strchr(b, *p))
                        return true;

        return false;
}

bool string_has_cc(const char *p, const char *ok) {
        assert(p);

        /*
         * Check if a string contains control characters. If 'ok' is
         * non-NULL it may be a string containing additional CCs to be
         * considered OK.
         */

        for (const char *t = p; *t; t++) {
                if (ok && strchr(ok, *t))
                        continue;

                if (char_is_cc(*t))
                        return true;
        }

        return false;
}

// static int write_ellipsis(char *buf, bool unicode) {
// assert(0);
//         if (unicode || is_locale_utf8()) {
//                 buf[0] = 0xe2; /* tri-dot ellipsis: … */
//                 buf[1] = 0x80;
//                 buf[2] = 0xa6;
//         } else {
//                 buf[0] = '.';
//                 buf[1] = '.';
//                 buf[2] = '.';
//         }
// 
//         return 3;
// }

// static char *ascii_ellipsize_mem(const char *s, size_t old_length, size_t new_length, unsigned percent) {
//         size_t x, need_space, suffix_len;
//         char *t;
// 
//         assert(s);
//         assert(percent <= 100);
//         assert(new_length != SIZE_MAX);
// 
//         if (old_length <= new_length)
//                 return strndup(s, old_length);
// 
//         /* Special case short ellipsations */
//         switch (new_length) {
// 
//         case 0:
//                 return strdup("");
// 
//         case 1:
//                 if (is_locale_utf8())
//                         return strdup("…");
//                 else
//                         return strdup(".");
// 
//         case 2:
//                 if (!is_locale_utf8())
//                         return strdup("..");
// 
//                 break;
// 
//         default:
//                 break;
//         }
// 
//         /* Calculate how much space the ellipsis will take up. If we are in UTF-8 mode we only need space for one
//          * character ("…"), otherwise for three characters ("..."). Note that in both cases we need 3 bytes of storage,
//          * either for the UTF-8 encoded character or for three ASCII characters. */
//         need_space = is_locale_utf8() ? 1 : 3;
// 
//         t = new(char, new_length+3);
//         if (!t)
//                 return NULL;
// 
//         assert(new_length >= need_space);
// 
//         x = ((new_length - need_space) * percent + 50) / 100;
//         assert(x <= new_length - need_space);
// 
//         memcpy(t, s, x);
//         write_ellipsis(t + x, false);
//         suffix_len = new_length - x - need_space;
//         memcpy(t + x + 3, s + old_length - suffix_len, suffix_len);
//         *(t + x + 3 + suffix_len) = '\0';
// 
//         return t;
// }

// char *ellipsize_mem(const char *s, size_t old_length, size_t new_length, unsigned percent) {
// // assert(0);
// return NULL;
// //         size_t x, k, len, len2;
// //         const char *i, *j;
// //         char *e;
// //         int r;
// // 
// //         /* Note that 'old_length' refers to bytes in the string, while 'new_length' refers to character cells taken up
// //          * on screen. This distinction doesn't matter for ASCII strings, but it does matter for non-ASCII UTF-8
// //          * strings.
// //          *
// //          * Ellipsation is done in a locale-dependent way:
// //          * 1. If the string passed in is fully ASCII and the current locale is not UTF-8, three dots are used ("...")
// //          * 2. Otherwise, a unicode ellipsis is used ("…")
// //          *
// //          * In other words: you'll get a unicode ellipsis as soon as either the string contains non-ASCII characters or
// //          * the current locale is UTF-8.
// //          */
// // 
// //         assert(s);
// //         assert(percent <= 100);
// // 
// //         if (new_length == SIZE_MAX)
// //                 return strndup(s, old_length);
// // 
// //         if (new_length == 0)
// //                 return strdup("");
// // 
// //         /* If no multibyte characters use ascii_ellipsize_mem for speed */
// //         if (ascii_is_valid_n(s, old_length))
// //                 return ascii_ellipsize_mem(s, old_length, new_length, percent);
// // 
// //         x = ((new_length - 1) * percent) / 100;
// //         assert(x <= new_length - 1);
// // 
// //         k = 0;
// //         for (i = s; i < s + old_length; i = utf8_next_char(i)) {
// //                 char32_t c;
// //                 int w;
// // 
// //                 r = utf8_encoded_to_unichar(i, &c);
// //                 if (r < 0)
// //                         return NULL;
// // 
// //                 w = unichar_iswide(c) ? 2 : 1;
// //                 if (k + w <= x)
// //                         k += w;
// //                 else
// //                         break;
// //         }
// // 
// //         for (j = s + old_length; j > i; ) {
// //                 char32_t c;
// //                 int w;
// //                 const char *jj;
// // 
// //                 jj = utf8_prev_char(j);
// //                 r = utf8_encoded_to_unichar(jj, &c);
// //                 if (r < 0)
// //                         return NULL;
// // 
// //                 w = unichar_iswide(c) ? 2 : 1;
// //                 if (k + w <= new_length) {
// //                         k += w;
// //                         j = jj;
// //                 } else
// //                         break;
// //         }
// //         assert(i <= j);
// // 
// //         /* we don't actually need to ellipsize */
// //         if (i == j)
// //                 return memdup_suffix0(s, old_length);
// // 
// //         /* make space for ellipsis, if possible */
// //         if (j < s + old_length)
// //                 j = utf8_next_char(j);
// //         else if (i > s)
// //                 i = utf8_prev_char(i);
// // 
// //         len = i - s;
// //         len2 = s + old_length - j;
// //         e = new(char, len + 3 + len2 + 1);
// //         if (!e)
// //                 return NULL;
// // 
// //         /*
// //         printf("old_length=%zu new_length=%zu x=%zu len=%u len2=%u k=%u\n",
// //                old_length, new_length, x, len, len2, k);
// //         */
// // 
// //         memcpy(e, s, len);
// //         write_ellipsis(e + len, true);
// //         memcpy(e + len + 3, j, len2);
// //         *(e + len + 3 + len2) = '\0';
// // 
// //         return e;
// }

// char *cellescape(char *buf, size_t len, const char *s) {
//         /* Escape and ellipsize s into buffer buf of size len. Only non-control ASCII
//          * characters are copied as they are, everything else is escaped. The result
//          * is different then if escaping and ellipsization was performed in two
//          * separate steps, because each sequence is either stored in full or skipped.
//          *
//          * This function should be used for logging about strings which expected to
//          * be plain ASCII in a safe way.
//          *
//          * An ellipsis will be used if s is too long. It was always placed at the
//          * very end.
//          */
// 
//         size_t i = 0, last_char_width[4] = {}, k = 0;
// 
//         assert(len > 0); /* at least a terminating NUL */
// 
//         for (;;) {
//                 char four[4];
//                 int w;
// 
//                 if (*s == 0) /* terminating NUL detected? then we are done! */
//                         goto done;
// 
//                 w = cescape_char(*s, four);
//                 if (i + w + 1 > len) /* This character doesn't fit into the buffer anymore? In that case let's
//                                       * ellipsize at the previous location */
//                         break;
// 
//                 /* OK, there was space, let's add this escaped character to the buffer */
//                 memcpy(buf + i, four, w);
//                 i += w;
// 
//                 /* And remember its width in the ring buffer */
//                 last_char_width[k] = w;
//                 k = (k + 1) % 4;
// 
//                 s++;
//         }
// 
//         /* Ellipsation is necessary. This means we might need to truncate the string again to make space for 4
//          * characters ideally, but the buffer is shorter than that in the first place take what we can get */
//         for (size_t j = 0; j < ELEMENTSOF(last_char_width); j++) {
// 
//                 if (i + 4 <= len) /* nice, we reached our space goal */
//                         break;
// 
//                 k = k == 0 ? 3 : k - 1;
//                 if (last_char_width[k] == 0) /* bummer, we reached the beginning of the strings */
//                         break;
// 
//                 assert(i >= last_char_width[k]);
//                 i -= last_char_width[k];
//         }
// 
//         if (i + 4 <= len) /* yay, enough space */
//                 i += write_ellipsis(buf + i, false);
//         else if (i + 3 <= len) { /* only space for ".." */
//                 buf[i++] = '.';
//                 buf[i++] = '.';
//         } else if (i + 2 <= len) /* only space for a single "." */
//                 buf[i++] = '.';
//         else
//                 assert(i + 1 <= len);
// 
//  done:
//         buf[i] = '\0';
//         return buf;
// }

char* strshorten(char *s, size_t l) {
        assert(s);

        if (strnlen(s, l+1) > l)
                s[l] = 0;

        return s;
}

// char *strreplace(const char *text, const char *old_string, const char *new_string) {
//         size_t l, old_len, new_len;
//         char *t, *ret = NULL;
//         const char *f;
// 
//         assert(old_string);
//         assert(new_string);
// 
//         if (!text)
//                 return NULL;
// 
//         old_len = strlen(old_string);
//         new_len = strlen(new_string);
// 
//         l = strlen(text);
//         if (!GREEDY_REALLOC(ret, l+1))
//                 return NULL;
// 
//         f = text;
//         t = ret;
//         while (*f) {
//                 size_t d, nl;
// 
//                 if (!startswith(f, old_string)) {
//                         *(t++) = *(f++);
//                         continue;
//                 }
// 
//                 d = t - ret;
//                 nl = l - old_len + new_len;
// 
//                 if (!GREEDY_REALLOC(ret, nl + 1))
//                         return mfree(ret);
// 
//                 l = nl;
//                 t = ret + d;
// 
//                 t = stpcpy(t, new_string);
//                 f += old_len;
//         }
// 
//         *t = 0;
//         return ret;
// }

// static void advance_offsets(
//                 ssize_t diff,
//                 size_t offsets[2], /* note: we can't use [static 2] here, since this may be NULL */
//                 size_t shift[static 2],
//                 size_t size) {
// 
//         if (!offsets)
//                 return;
// 
//         assert(shift);
// 
//         if ((size_t) diff < offsets[0])
//                 shift[0] += size;
//         if ((size_t) diff < offsets[1])
//                 shift[1] += size;
// }

// char *strip_tab_ansi(char **ibuf, size_t *_isz, size_t highlight[2]) {
//         const char *begin = NULL;
//         enum {
//                 STATE_OTHER,
//                 STATE_ESCAPE,
//                 STATE_CSI,
//                 STATE_CSO,
//         } state = STATE_OTHER;
//         char *obuf = NULL;
//         size_t osz = 0, isz, shift[2] = {}, n_carriage_returns = 0;
//         FILE *f;
// 
//         assert(ibuf);
//         assert(*ibuf);
// 
//         /* This does three things:
//          *
//          * 1. Replaces TABs by 8 spaces
//          * 2. Strips ANSI color sequences (a subset of CSI), i.e. ESC '[' … 'm' sequences
//          * 3. Strips ANSI operating system sequences (CSO), i.e. ESC ']' … BEL sequences
//          * 4. Strip trailing \r characters (since they would "move the cursor", but have no
//          *    other effect).
//          *
//          * Everything else will be left as it is. In particular other ANSI sequences are left as they are, as
//          * are any other special characters. Truncated ANSI sequences are left-as is too. This call is
//          * supposed to suppress the most basic formatting noise, but nothing else.
//          *
//          * Why care for CSO sequences? Well, to undo what terminal_urlify() and friends generate. */
// 
//         isz = _isz ? *_isz : strlen(*ibuf);
// 
//         /* Note we turn off internal locking on f for performance reasons. It's safe to do so since we
//          * created f here and it doesn't leave our scope. */
//         f = open_memstream_unlocked(&obuf, &osz);
//         if (!f)
//                 return NULL;
// 
//         for (const char *i = *ibuf; i < *ibuf + isz + 1; i++) {
// 
//                 switch (state) {
// 
//                 case STATE_OTHER:
//                         if (i >= *ibuf + isz) /* EOT */
//                                 break;
// 
//                         if (*i == '\r') {
//                                 n_carriage_returns++;
//                                 break;
//                         } else if (*i == '\n')
//                                 /* Ignore carriage returns before new line */
//                                 n_carriage_returns = 0;
//                         for (; n_carriage_returns > 0; n_carriage_returns--)
//                                 fputc('\r', f);
// 
//                         if (*i == '\x1B')
//                                 state = STATE_ESCAPE;
//                         else if (*i == '\t') {
//                                 fputs("        ", f);
//                                 advance_offsets(i - *ibuf, highlight, shift, 7);
//                         } else
//                                 fputc(*i, f);
// 
//                         break;
// 
//                 case STATE_ESCAPE:
//                         assert(n_carriage_returns == 0);
// 
//                         if (i >= *ibuf + isz) { /* EOT */
//                                 fputc('\x1B', f);
//                                 advance_offsets(i - *ibuf, highlight, shift, 1);
//                                 break;
//                         } else if (*i == '[') { /* ANSI CSI */
//                                 state = STATE_CSI;
//                                 begin = i + 1;
//                         } else if (*i == ']') { /* ANSI CSO */
//                                 state = STATE_CSO;
//                                 begin = i + 1;
//                         } else {
//                                 fputc('\x1B', f);
//                                 fputc(*i, f);
//                                 advance_offsets(i - *ibuf, highlight, shift, 1);
//                                 state = STATE_OTHER;
//                         }
// 
//                         break;
// 
//                 case STATE_CSI:
//                         assert(n_carriage_returns == 0);
// 
//                         if (i >= *ibuf + isz || /* EOT … */
//                             !strchr("01234567890;m", *i)) { /* … or invalid chars in sequence */
//                                 fputc('\x1B', f);
//                                 fputc('[', f);
//                                 advance_offsets(i - *ibuf, highlight, shift, 2);
//                                 state = STATE_OTHER;
//                                 i = begin-1;
//                         } else if (*i == 'm')
//                                 state = STATE_OTHER;
// 
//                         break;
// 
//                 case STATE_CSO:
//                         assert(n_carriage_returns == 0);
// 
//                         if (i >= *ibuf + isz || /* EOT … */
//                             (*i != '\a' && (uint8_t) *i < 32U) || (uint8_t) *i > 126U) { /* … or invalid chars in sequence */
//                                 fputc('\x1B', f);
//                                 fputc(']', f);
//                                 advance_offsets(i - *ibuf, highlight, shift, 2);
//                                 state = STATE_OTHER;
//                                 i = begin-1;
//                         } else if (*i == '\a')
//                                 state = STATE_OTHER;
// 
//                         break;
//                 }
//         }
// 
//         if (fflush_and_check(f) < 0) {
//                 fclose(f);
//                 return mfree(obuf);
//         }
//         fclose(f);
// 
//         free_and_replace(*ibuf, obuf);
// 
//         if (_isz)
//                 *_isz = osz;
// 
//         if (highlight) {
//                 highlight[0] += shift[0];
//                 highlight[1] += shift[1];
//         }
// 
//         return *ibuf;
// }

// char *strextend_with_separator_internal(char **x, const char *separator, ...) {
//         size_t f, l, l_separator;
//         bool need_separator;
//         char *nr, *p;
//         va_list ap;
// 
//         assert(x);
// 
//         l = f = strlen_ptr(*x);
// 
//         need_separator = !isempty(*x);
//         l_separator = strlen_ptr(separator);
// 
//         va_start(ap, separator);
//         for (;;) {
//                 const char *t;
//                 size_t n;
// 
//                 t = va_arg(ap, const char *);
//                 if (!t)
//                         break;
// 
//                 n = strlen(t);
// 
//                 if (need_separator)
//                         n += l_separator;
// 
//                 if (n >= SIZE_MAX - l) {
//                         va_end(ap);
//                         return NULL;
//                 }
// 
//                 l += n;
//                 need_separator = true;
//         }
//         va_end(ap);
// 
//         need_separator = !isempty(*x);
// 
//         nr = realloc(*x, GREEDY_ALLOC_ROUND_UP(l+1));
//         if (!nr)
//                 return NULL;
// 
//         *x = nr;
//         p = nr + f;
// 
//         va_start(ap, separator);
//         for (;;) {
//                 const char *t;
// 
//                 t = va_arg(ap, const char *);
//                 if (!t)
//                         break;
// 
//                 if (need_separator && separator)
//                         p = stpcpy(p, separator);
// 
//                 p = stpcpy(p, t);
// 
//                 need_separator = true;
//         }
//         va_end(ap);
// 
//         assert(p == nr + l);
// 
//         *p = 0;
// 
//         return p;
// }

int strextendf_with_separator(char **x, const char *separator, const char *format, ...) {
        size_t m, a, l_separator;
        va_list ap;
        int l;

        /* Appends a formatted string to the specified string. Don't use this in inner loops, since then
         * we'll spend a tonload of time in determining the length of the string passed in, over and over
         * again. */

        assert(x);
        assert(format);

        l_separator = isempty(*x) ? 0 : strlen_ptr(separator);

        /* Let's try to use the allocated buffer, if there's room at the end still. Otherwise let's extend by 64 chars. */
        if (*x) {
                m = strlen(*x);
                a = MALLOC_SIZEOF_SAFE(*x);
                assert(a >= m + 1);
        } else
                m = a = 0;

        if (a - m < 17 + l_separator) { /* if there's less than 16 chars space, then enlarge the buffer first */
                char *n;

                if (_unlikely_(l_separator > SIZE_MAX - 64)) /* overflow check #1 */
                        return -ENOMEM;
                if (_unlikely_(m > SIZE_MAX - 64 - l_separator)) /* overflow check #2 */
                        return -ENOMEM;

                n = realloc(*x, m + 64 + l_separator);
                if (!n)
                        return -ENOMEM;

                *x = n;
                a = MALLOC_SIZEOF_SAFE(*x);
        }

        /* Now, let's try to format the string into it */
        memcpy_safe(*x + m, separator, l_separator);
        va_start(ap, format);
        l = vsnprintf(*x + m + l_separator, a - m - l_separator, format, ap);
        va_end(ap);

        assert(l >= 0);

        if ((size_t) l < a - m - l_separator) {
                char *n;

                /* Nice! This worked. We are done. But first, let's return the extra space we don't
                 * need. This should be a cheap operation, since we only lower the allocation size here,
                 * never increase. */
                n = realloc(*x, m + (size_t) l + l_separator + 1);
                if (n)
                        *x = n;
        } else {
                char *n;

                /* Wasn't enough. Then let's allocate exactly what we need. */

                if (_unlikely_((size_t) l > SIZE_MAX - (l_separator + 1))) /* overflow check #1 */
                        goto oom;
                if (_unlikely_(m > SIZE_MAX - ((size_t) l + l_separator + 1))) /* overflow check #2 */
                        goto oom;

                a = m + (size_t) l + l_separator + 1;
                n = realloc(*x, a);
                if (!n)
                        goto oom;
                *x = n;

                va_start(ap, format);
                l = vsnprintf(*x + m + l_separator, a - m - l_separator, format, ap);
                va_end(ap);

                assert((size_t) l < a - m - l_separator);
        }

        return 0;

oom:
        /* truncate the bytes added after the first vsnprintf() attempt again */
        (*x)[m] = 0;
        return -ENOMEM;
}

char *strrep(const char *s, unsigned n) {
        char *r, *p;
        size_t l;

        assert(s);

        l = strlen(s);
        p = r = malloc(l * n + 1);
        if (!r)
                return NULL;

        for (unsigned i = 0; i < n; i++)
                p = stpcpy(p, s);

        *p = 0;
        return r;
}

int split_pair(const char *s, const char *sep, char **l, char **r) {
        char *x, *a, *b;

        assert(s);
        assert(sep);
        assert(l);
        assert(r);

        if (isempty(sep))
                return -EINVAL;

        x = strstr(s, sep);
        if (!x)
                return -EINVAL;

        a = strndup(s, x - s);
        if (!a)
                return -ENOMEM;

        b = strdup(x + strlen(sep));
        if (!b) {
                free(a);
                return -ENOMEM;
        }

        *l = a;
        *r = b;

        return 0;
}

int free_and_strdup(char **p, const char *s) {
        char *t;

        assert(p);

        /* Replaces a string pointer with a strdup()ed new string,
         * possibly freeing the old one. */

        if (streq_ptr(*p, s))
                return 0;

        if (s) {
                t = strdup(s);
                if (!t)
                        return -ENOMEM;
        } else
                t = NULL;

        free(*p);
        *p = t;

        return 1;
}

// int free_and_strndup(char **p, const char *s, size_t l) {
//         char *t;
// 
//         assert(p);
//         assert(s || l == 0);
// 
//         /* Replaces a string pointer with a strndup()ed new string,
//          * freeing the old one. */
// 
//         if (!*p && !s)
//                 return 0;
// 
//         if (*p && s && strneq(*p, s, l) && (l > strlen(*p) || (*p)[l] == '\0'))
//                 return 0;
// 
//         if (s) {
//                 t = strndup(s, l);
//                 if (!t)
//                         return -ENOMEM;
//         } else
//                 t = NULL;
// 
//         free_and_replace(*p, t);
//         return 1;
// }

bool string_is_safe(const char *p) {
        if (!p)
                return false;

        /* Checks if the specified string contains no quotes or control characters */

        for (const char *t = p; *t; t++) {
                if (*t > 0 && *t < ' ') /* no control characters */
                        return false;

                if (strchr(QUOTES "\\\x7f", *t))
                        return false;
        }

        return true;
}

char* string_erase(char *x) {
        if (!x)
                return NULL;

        /* A delicious drop of snake-oil! To be called on memory where we stored passphrases or so, after we
         * used them. */
        explicit_bzero_safe(x, strlen(x));
        return x;
}

int string_truncate_lines(const char *s, size_t n_lines, char **ret) {
        const char *p = s, *e = s;
        bool truncation_applied = false;
        char *copy;
        size_t n = 0;

        assert(s);

        /* Truncate after the specified number of lines. Returns > 0 if a truncation was applied or == 0 if
         * there were fewer lines in the string anyway. Trailing newlines on input are ignored, and not
         * generated either. */

        for (;;) {
                size_t k;

                k = strcspn(p, "\n");

                if (p[k] == 0) {
                        if (k == 0) /* final empty line */
                                break;

                        if (n >= n_lines) /* above threshold */
                                break;

                        e = p + k; /* last line to include */
                        break;
                }

                assert(p[k] == '\n');

                if (n >= n_lines)
                        break;

                if (k > 0)
                        e = p + k;

                p += k + 1;
                n++;
        }

        /* e points after the last character we want to keep */
        if (isempty(e))
                copy = strdup(s);
        else {
                if (!in_charset(e, "\n")) /* We only consider things truncated if we remove something that
                                           * isn't a new-line or a series of them */
                        truncation_applied = true;

                copy = strndup(s, e - s);
        }
        if (!copy)
                return -ENOMEM;

        *ret = copy;
        return truncation_applied;
}

int string_extract_line(const char *s, size_t i, char **ret) {
        const char *p = s;
        size_t c = 0;

        /* Extract the i'nth line from the specified string. Returns > 0 if there are more lines after that,
         * and == 0 if we are looking at the last line or already beyond the last line. As special
         * optimization, if the first line is requested and the string only consists of one line we return
         * NULL, indicating the input string should be used as is, and avoid a memory allocation for a very
         * common case. */

        for (;;) {
                const char *q;

                q = strchr(p, '\n');
                if (i == c) {
                        /* The line we are looking for! */

                        if (q) {
                                char *m;

                                m = strndup(p, q - p);
                                if (!m)
                                        return -ENOMEM;

                                *ret = m;
                                return !isempty(q + 1); /* more coming? */
                        } else {
                                if (p == s)
                                        *ret = NULL; /* Just use the input string */
                                else {
                                        char *m;

                                        m = strdup(p);
                                        if (!m)
                                                return -ENOMEM;

                                        *ret = m;
                                }

                                return 0; /* The end */
                        }
                }

                if (!q) {
                        char *m;

                        /* No more lines, return empty line */

                        m = strdup("");
                        if (!m)
                                return -ENOMEM;

                        *ret = m;
                        return 0; /* The end */
                }

                p = q + 1;
                c++;
        }
}

// int string_contains_word_strv(const char *string, const char *separators, char **words, const char **ret_word) {
//         /* In the default mode with no separators specified, we split on whitespace and
//          * don't coalesce separators. */
//         const ExtractFlags flags = separators ? EXTRACT_DONT_COALESCE_SEPARATORS : 0;
// 
//         const char *found = NULL;
// 
//         for (const char *p = string;;) {
//                 _cleanup_free_ char *w = NULL;
//                 int r;
// 
//                 r = extract_first_word(&p, &w, separators, flags);
//                 if (r < 0)
//                         return r;
//                 if (r == 0)
//                         break;
// 
//                 found = strv_find(words, w);
//                 if (found)
//                         break;
//         }
// 
//         if (ret_word)
//                 *ret_word = found;
//         return !!found;
// }
